My foremost appreciation goes to the artists who have collaborated with Gemini G.E.L. Their work provides the essential impetus for this catalogue raisonné and is a constant source of visual enrichment to staff and visitors alike. I also deeply appreciate the extraordinary generosity of Sidney B. Felsen and Stanley Grinstein, who have contributed profoundly to the National Gallery's collection of contemporary art by establishing the Gemini G.E.L. Archive. Stanley's interest and enthusiasm were a continually motivating force, while Sidney lavished great attention on my persistent requests for information and generously supplied his wonderful documentary photographs of Gemini through the years.

I want to thank Joni Moisant Weyl for her enthusiastic support. In addition, a deep bow of appreciation goes to many members of the Gemini G.E.L. staff for their extraordinary contributions. In particular, Nancy Ervin, who cheerfully gathered images and information and supplied much background about the works, as well as James Reid, master printer, who consistently provided thoughtful technical insight into the Gemini oeuvre. Many other Gemini staff assisted over the course of this project with important contributions made by Talia Avisar, Suzanne Felsen, Dorothy Halic, Philip Martin, David McDaniel, Ronald McPherson, Octavio Molina, Rebecca Ratzkin, Tom Schirtz, Fran Salomon, Carmelita Seaman, Claudio Stickar, Karin Strelioff, and Ashley Teplin. A special thanks also goes to Doug Parker, the long-time Gemini photographer who has shaped our view of many of the atelier's works. My heartfelt thanks also go to others of the staff who have contributed both directly and indirectly to the realization of this undertaking. I would additionally like to thank Michael Ester at Luna Imaging Inc. for the beauty of the scans his organization provided. Members of his staff provided fine assistance. Among these, Jordan Lane was extremely helpful during production, as was Lori Richmeier, who gave additional support.

At the National Gallery I thank Earl A. Powell III, director, Alan Shestack, deputy director, and Andrew Robison, Andrew W. Mellon Senior Curator of Prints and Drawings. They have strongly supported this project. Ruth E. Fine, curator of modern prints and drawings, has been a constant source of expertise, information, energy, and encouragement. She has been actively involved in every aspect in the formation of this resource. I would also like to thank other members of our staff for their help: Carlotta J. Owens, assistant curator of modern prints and drawings, made a substantial contribution in sustaining much of the day-to-day department operations while this catalogue came to fruition. Tom Coolsen, Mary Lee Corlett, Victoria Foster, Ava Lambert, Jane O'Meara, Judy Szypa, and Ani Bedrossian, present and former department members, contributed in myriad ways to this achievement. The interns who worked with the Gemini G.E.L. Archive have been many, but an especially great debt is owed to Claude L. Elliott, who during his tenure with us did much to structure this manuscript and image collection. Other important intern contributors were Kimberly Bockhaus, Susan Funkenstein, Ilaria Fusina, Mikka Gee, Amy Gotzler, Vanessa Jones, Maria Los, Eileen McKiernan Gonzales, Alison Pace, Katja Zigerlig, and Elizabeth Zopf.

For guidance with the production of this catalogue, I thank Judy Metro, the Gallery's editor in chief for her steady support, as well as Frances Smyth-Ravenel, who was editor in chief when the project began. The sensitive and intelligent production by Web manager Phyllis Hecht has been an essential ingredient in the success of this endeavor, as has the impeccable design of our very talented Melissa Front, and the astute editorial guidance of Clare Parsons. In addition, I want to thank Ric Foster for sharing his remarkable abilities with computer software; he has made this task far easier than it would have been without his insight and invention. I also thank Judith Walsh for the invaluable contribution she made in reviewing and researching the many papers and other supports used for printing by Gemini. In addition, I am deeply grateful to former editors Tam Curry Bryfogle, Amy Pastan, and Jane Sweeney for their help with various portions of this project, and I thank Leo Kasun of our extension programs department for his editorial comments. I also thank Mark Rosenthal, former curator of twentieth-century art. During his tenure, the sharing of his expertise and thoughts on Gemini were extremely useful. I am grateful as well to The Circle of the National Gallery of Art for providing funds for the image scanning for this catalogue.

In the Gallery's department of photography and digital imaging services there are many gifted individuals to thank who provided photographs of the Gemini works over the years. These include Richard Amt, Ricardo Blanc, Dean Beasom, Philip Charles, Lorene Emerson, Lee Ewing, Bob Grove, José Naranjo, and William Wilson. For administrative assistance with photography from our visual services department, I also want to thank Ira Bartfield, Barbara Bernard, Sara Sanders-Buell, Peter Huestis, Sarah Sibbald, Nancy Stanfield, and Barbara Goldstein Wood. In addition, outside the National Gallery, I would like to thank the image applications department at IBM's Watson Research Center that provided the code used to reduce and sharpen images for the thumbnail production process that was used to produce this catalogue.

And finally I thank Virginia Ritchie and our daughter Samantha for their endless patience, love, and support.